Myelodysplastic syndromes (MDS) are myeloid neoplasms characterized by clonal proliferation of hematopoietic stem cells, recurrent genetic abnormalities, myelodysplasia, ineffective hematopoiesis, peripheral-blood cytopenia, and a high risk of evolution to acute myeloid leukemia (AML).
Diagnostic Criteria for Myeloid Neoplasms with Myelodysplasia and Precursor Conditions for Myelodysplastic syndromes red 5px solid(MDS)
|Myeloid neoplasms with myelodysplasia|
|MDS||Persistent cytopenia in one or more peripheral-blood cell lineages and morphologic dysplasia (≥10% dysplastic cells) in one or more bone marrow cell lineages; on the basis of morphologic and cytogenetic abnormalities, MDS are categorized into the following subtypes:
MDS with single-lineage dysplasia
MDS with multilineage dysplasia
MDS with ring sideroblasts and single-lineage dysplasia or multilineage dysplasia
MDS with isolated del(5q)
MDS with excess blasts type 1 or type 2
|Myelodysplastic–myeloproliferative neoplasms||Myeloid neoplasms with clinical, laboratory, and morphologic features that overlap those of MDS and myeloproliferative neoplasms; myelodysplastic–myeloproliferative neoplasms are divided into the following subtypes:
Chronic myelomonocytic leukemia
BCR-ABL1–negative atypical chronic myeloid leukemia
Myelodysplastic–myeloproliferative neoplasm with ring sideroblasts and thrombocytosis
Juvenile myelomonocytic leukemia
|Therapy-related myeloid neoplasms||MDS, myelodysplastic–myeloproliferative neoplasms, and acute myeloid leukemia that occur as late complications of chemotherapy or radiotherapy|
|MDS precursor conditions|
|Clonal Hematopoiesis of Indeterminate Potential (CHIP)||Normal peripheral-blood cell counts with a somatic mutation, at a variant allele frequency of at least 2%, in a gene that is recurrently mutated in myeloid neoplasms‡|
|Clonal Cytopenia of Undetermined Significance (CCUS)||Unexplained cytopenia in one or more peripheral-blood cell lineages; a somatic mutation, at a variant allele frequency of at least 20%, in one or more genes that are recurrently mutated in myeloid neoplasms; and insufficient WHO criteria for a diagnosis of MDS, essentially because of lack of overt dysplasia (<10% dysplastic cells in any bone marrow cell lineage), excess blasts, and MDS-defining chromosomal abnor-malities §|
‡ Persons with CHIP may have increased values for red-cell distribution width.
§ Although a variant allele frequency of at least 2% was initially suggested for the diagnosis of CCUS, the available evidence indicates that a higher cutoff point (20%) should be used to identify clinically significant clonality.
- Cazzola M. Myelodysplastic Syndromes. N Engl J Med. 2020 Oct 1;383(14):1358-1374. [Medline]
- Shreve J, Nazha A. Novel Prognostic Models for Myelodysplastic Syndromes. Hematol Oncol Clin North Am. 2020 Apr;34(2):369-378. [Medline]
Created Nov 26, 2020.